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Allyance

Contributor
Sep 29, 2017
2,074
7,662
East Bay, CA
For a two pin AC power socket does it matter if live snd neutral are reversed.
Normally it shouldn't. By the electrical code the "neutral" should be grounded only ONCE, at the electrical panel demarcation point to your power provider. Some two prong power cords are polarized so that the neutral is connected to the proper side of the device circuit. What you are feeling are mild voltages caused by ground loops from other devices. There tester you can get at Lowes that will tell you if the "neutral" is grounded at a secondary point (mis-wired outlet, etc) in your home. These ground loops can play havoc with audio systems when a grounded component is connected to an amplifier. I had to use an isolation transformer between my old iMac and my home theater receiver because of the hum.
 

BanditoB

macrumors 6502
Feb 24, 2009
482
258
Chicago, IL
This absolutely is not normal behavior. Do you have a voltage meter? You could try to measure the voltage that the Mac’s chassis is delivering. If it’s above zero (not accounting for a bit of noise), something is wrong with the Mac. Get it serviced right away.
 

uandme72

macrumors 68020
Original poster
Mar 2, 2015
2,077
684
This absolutely is not normal behavior. Do you have a voltage meter? You could try to measure the voltage that the Mac’s chassis is delivering. If it’s above zero (not accounting for a bit of noise), something is wrong with the Mac. Get it serviced right away.
I have tried it on multiple macs. All exhibit same behaviour.
 

Fishrrman

macrumors Penryn
Feb 20, 2009
29,239
13,311
There have been reports/complaints for years about "that tingling sensation" when a Mac laptop is connected to a wall outlet with a 2-prong plug.

Use Apple's 3-prong "extension" (that plugs into the charger block), and the tingling... disappears.

That's because the connection is now fully grounded (hot wire, neutral, ground).

Of course the 3-prong 110v plug is unique to the United States, Canada, perhaps Central/South America (I have no idea about south of the American border).

I don't know how Europeans (with their strange 220v 2-prong plugs) handle this...
 

BanditoB

macrumors 6502
Feb 24, 2009
482
258
Chicago, IL
I’d still recommend that you put a meter on it to see if anything is really there. Perhaps you are particularly sensitive to voltages? Either way, it still shouldn’t do this.
 

JesseBruffett

macrumors newbie
Jun 22, 2022
16
12
It's most likely a ground issue or ground loop with your house or apartments electric. I have been using only the 3 prong cables since 2011 when I started using Mac's, ive also lived in this apt since then too and ive had this issue with every Mac ive owned. If you're worried take it to the store and verify that the charger and machine are fine, beyond that either deal with it OR call an electrician to figure out the grounding issue.
 

shimpster

macrumors regular
Sep 18, 2018
100
82
I don't get this on my M1 MacBook Pro (probably cause I have had the three pronged extension cable) but I get this all the time on my iPhones, iPads, and interestingly enough I get it on my Air Pods Max. Very Interesting to learn the reason.
 

dandeco

macrumors 65816
Dec 5, 2008
1,253
1,050
Brockton, MA
A common problem with almost all aluminium based electronic devices. Nothing to worry about. Although, it's better to let it be while charging.
Yeah, I've felt that with a few other aluminum MacBooks and older iPads, including my own and ones at my workplace.
 
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